<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
		
		*{
			padding: 0;
			margin: 0;
		}
		div{
			width: 200px;
			height: 200px;

		}
		.box1{
			background-color: red;

			/*绝对的定位： 1.脱标
			2.做遮盖效果，提升层级
			 3.设置绝对定位之后，不区分行内元素和块级元素，都能设置宽高。
			*/
			position: absolute;
		}
		.box2{
			background-color: green;
			
		}
		.box3{
			background-color: blue;
		}
		span{
			width: 100px;
			height: 100px;
			background-color: pink;
			position: absolute;
		}


	</style>
</head>
<body>

	

	<div class="box1"></div>
	<div class="box2"></div>
	<div class="box3"></div>
	<span>文字</span>
	
</body>
</html>